Risks of Syrian Intervention Limit Options for U.S.

WASHINGTON — Despite President Obama’s warning to Syria not to use its arsenal of chemical weapons or allow them to fall into the hands of extremists, the administration’s options for intervening remain limited by what its officials have described as a simple calculus: It would make the conflict even worse.

American military operations against Syria, officials reiterated on Tuesday, would risk drawing in Syria’s patrons, principally Iran and Russia, at a much greater level than they already are involved. It would allow Syria’s president, Bashar al-Assad, to rally popular sentiment against the West and embolden Al Qaeda and other terrorist groups now fighting the Assad government to turn their attention to what they would see as another American crusade in the Arab world.

Syria’s deputy prime minister, Qadri Jamil, made the point in Moscow on Tuesday, dismissing Mr. Obama’s warning, and declaring that any foreign military intervention would lead to “a confrontation wider than Syria’s borders.”

At the same time, Mr. Obama’s remarks underscored the fact that there could be limits to the American reluctance to intervene. But it would require a threat to American interests and values that a civil war inside Syria by itself does not: a nightmarish attack using chemical weapons or the transfer of those weapons to hardened enemies of the United States and its allies, including Israel, which the president mentioned on Monday.

“We say it for deterrence effect, of course, but it’s also a reality,” one official said Tuesday, speaking on condition of anonymity to discuss the administration’s internal strategy deliberations. “The United States is not going to be able to sit it out if Syria starts using chemical weapons on its people.”

The Syrian Foreign Ministry pledged in late July that its stockpile of chemical weapons would be used only against foreign intervention, and that it would “never, never be used against the Syrian people or civilians during this crisis, under any circumstances.”

Some experts and lawmakers have urged the administration to do more, including prominent members of Congress like Senator John McCain of Arizona, who called last month for increasing intelligence and helping to create “safe zones” in rebel-held areas. The White House faces little real public or political pressure to intervene forcefully, though, even as the bloodshed worsens.

Mr. McCain was a frequent critic of what he regarded as the Obama administration’s overly cautious policy toward Libya, which did lead to military intervention by NATO. But, the officials said, the conflict in Syria has become far more complicated than was the case in Libya. That country’s universally unpopular leader, Col. Muammar el-Qaddafi, had neither an effective military nor international backing, and it posed far less risk of ethnic and sectarian strife that could easily spill into Syria’s neighbors, including Lebanon, Jordan, Iraq, Turkey and Israel.

For now, the legal and diplomatic hurdles to intervention remain insurmountable. In large part because of the intervention in Libya, Russia and China have vowed to block United Nations authorization that could lead to international military involvement, something that European allies from Britain to Turkey insist is a prerequisite for international intervention.

At the Pentagon, commanders continue to draft plans for potential operations — from establishing a “no fly” zone, as in Libya, or sending in special forces to neutralize Syria’s unconventional weapons, should they be used or moved out of the Syrian government’s control. Pentagon officials have indicated that a worst-case scenario would require tens of thousands of soldiers, something that the officials said would inflame an already roiling region.

Mr. Obama did not explicitly threaten a military response in the event of a chemical weapons attack, though he called it a “red line” that would “change my calculus” about the American response so far. Such an attack, the officials said, would also change the thinking of other nations, including Russia, and raise the chances of an international reaction.

The administration’s current policy involves intensifying diplomatic and economic pressure on Mr. Assad’s government through sanctions, offering humanitarian assistance to Syrians inside and outside the country, and providing $25 million in “nonlethal” help to Mr. Assad’s opponents, including more recently to members of the Free Syrian Army. That aid has paid for communication equipment to enable the armed and unarmed opposition to better coordinate their attacks and plans for taking power.

The administration has also ruled out providing arms to the rebels for broadly the same reason: more weapons, the officials say, would probably make the war only worse.

Some rebels, for example, have asked for portable rocket launchers known as Manpads, which experts say could make a huge difference in the fighting by countering government jet and helicopter attacks. But the officials point to the experience of Afghanistan in the 1980s, when the Central Intelligence Agency provided Stinger missiles to the mujahedeen fighting the Soviet Union, only to spend millions trying to track them down after the Soviets left and the opposition groups gave rise to the Taliban.

“The complexity of Syria today makes Afghanistan in 1985 look very simple,” said Milton A. Bearden, who helped oversee the C.I.A.’s clandestine support of Afghan fighters in the 1980s, including the Stingers. “Who is the Syrian opposition? Who would these weapons go to?”

The risk of not doing more is that the United States could lose the support of those hoping to overthrow Mr. Assad — in contrast to Libya’s new leaders, who now view the Americans favorably. There is also a moral argument that the United States and NATO intervened in Libya because it was easy, but not in Syria because it was hard. While some administration officials privately express frustration that the conflict is spiraling ever deeper out of control, they say it only underscores the danger of being drawn into a larger regional or even international conflict.

“The opposition desperately needs weapons if you don’t want this conflict to be a grinder, which is the trajectory now,” Andrew J. Tabler, a Syria expert at the Washington Institute for Near East Policy, said in a telephone interview from Beirut. “If you’re not going to make the choice to intervene, you need to give them the ability to end this conflict themselves.”

The administration maintains it is doing what is feasible to hasten the end of Mr. Assad’s rule, while the Pentagon and State Department plan for the political transition that would follow, addressing such questions as the security of Syria’s chemical arsenal. Other covert operations are also under way, though their extent remains unknown.

“I reject the zero-sum argument,” one official said on Tuesday, “where either you intervene militarily or you’re doing nothing.”

A version of this news analysis appears in print on August 22, 2012, on page A6 of the New York edition with the headline: Inflammatory Risks of Syrian Intervention Limit Options for U.S. Order Reprints|Today's Paper|Subscribe